KR20150017649A - Adhesive composition and complexed polarization plate using the same - Google Patents

Abstract

The present invention relates to an adhesive composition and a complex polarization plate using the same. More specifically, the present invention relates to an adhesive composition, which includes a photopolymerizable compound having a hydroxyl group or a carboxyl group and acrylic based monomers having 6 to 18 carbon numbers on an aromatic group; and an photopolymerizable initiator, thereby improving an adhesive force between polarizers and patterned phase difference layers, when the adhesive is used for a manufacturing a complex polarization plate by connecting the polarizers to the patterned phase difference layer, and heat resistance and moisture-heat resistance and having three-dimensional effects, and a complex polarization plate using the same.

Description

TECHNICAL FIELD [0001] The present invention relates to an adhesive composition and a composite polarizer using the adhesive composition.

The present invention relates to an adhesive composition and a composite polarizer using the same.

In a display such as a liquid crystal display for stereoscopic image implementation, a patterned retardation film is often included. The patterned retardation film realizes a stereoscopic image by configuring the optical axes of the respective pattern regions in different directions so that images transmitted to the left and right eyes of the viewer wearing polarized glasses are different.

The patterned retardation film can be usually formed by forming an alignment film on a glass substrate and coating and orienting a liquid crystal on the alignment film. The photoreactive liquid crystal material is oriented on the alignment layer and then crosslinked by light irradiation such as ultraviolet rays to form a polymer liquid crystal film. At this time, the retarder pattern functions in accordance with the alignment direction of the liquid crystal in accordance with the surface orientation of the alignment film.

The patterned retardation film is usually bonded to one side of a polarizing plate via an adhesive or a pressure-sensitive adhesive, and is recently bonded to one side of a polyvinyl alcohol polarizer for further thin film lightening.

If the patterned retardation film is inferior in adhesion between the polarizing plate and the polarizer, deformation may occur during handling or during use in the process, and peeling or bumping may occur when the film is exposed to high temperature and high humidity for a long time. In addition, a conventional polyvinyl alcohol polarizer can shrink in the stretching direction, so that the retardation differs depending on the position of the retardation layer, and the 3D stereoscopic effect may be lowered.

Further, when the product is exposed to moisture for a long time due to condensation, water retention, or the like during long-term storage or transportation of the manufactured product, peeling occurs between the patterned retardation film adhered via the adhesive and the polarizer .

Accordingly, there is a demand for development of an excellent adhesive having excellent bonding strength, excellent functions such as resistance to water temperature and resistance to humidity, and the like.

Korean Patent Laid-Open Publication No. 2013-0028881 discloses a method for producing a film pattern reliader and a film pattern reliator, and a polarizing plate and an image display device having the film pattern reliator.

Patent Document 1: Korean Patent Publication No. 2013-0028881

It is an object of the present invention to provide an adhesive composition capable of remarkably improving the bonding force between a polarizer and a patterned retardation layer when used to manufacture a composite polarizing plate by bonding a polarizer and a patterned retardation layer.

An object of the present invention is to provide an adhesive composition capable of remarkably improving the durability of a composite polarizing plate such as heat resistance, heat resistance, humidity resistance and water resistance.

It is an object of the present invention to provide a composite polarizing plate bonded through the above adhesive composition.

1. a photopolymerizable compound comprising a hydroxyl group or an acrylic monomer having a carboxyl group and an aromatic ring having 6 to 18 carbon atoms; And a photopolymerization initiator.

2. The adhesive composition according to 1 above, wherein the acrylic monomer is at least one of compounds represented by the following general formulas (1) and (2)

[Chemical Formula 1]

(Wherein R < ₁ > is hydrogen or a methyl group,

X is oxygen, -NH- or -COO-,

R ₂ is an aryl group having 6 to 18 carbon atoms which may be substituted with an alkyl group having 1 to 5 carbon atoms, a hydroxyl group, a carboxyl group or a phenyl isopropyl group)

(2)

(Wherein R < ₃ > is hydrogen or a methyl group,

X is oxygen or -NH-,

R ₄ is an alkylene group having 1 to 5 carbon atoms, which can be interrupted by -CO- or -COO-,

And R < ₅ > is an aryl group having 6 to 18 carbon atoms substituted with a hydroxy group or a carboxy group).

3. The adhesive composition of 1 above, wherein said photopolymerizable compound further comprises a monomer represented by the following formula (4):

[Chemical Formula 4]

(Wherein R ₈ is hydrogen or a methyl group, X is oxygen or -NH-, R ₉ is a straight or branched alkylene group having 1 to 6 carbon atoms, and is interrupted by a cycloalkylene group having 3 to 6 carbon atoms Lt; / RTI >

4. The adhesive composition of 1 above, wherein said photopolymerizable compound further comprises a monomer represented by at least one of the following formulas (6) and (7):

[Chemical Formula 6]

(Wherein R < ₁₁ > is hydrogen or a methyl group),

(7)

(Wherein R ₁₂ is hydrogen or a methyl group, X is oxygen or -NH-,

R ₁₃ is a linear or branched alkylene group having 1 to 6 carbon atoms or a linear or branched alkenylene group having 2 to 6 carbon atoms and may be interrupted by -COO- or a cycloalkylene group having 3 to 6 carbon atoms) .

5. The adhesive composition according to item 3, wherein the hydroxyl group or the carboxyl group and the acrylic monomer having an aromatic ring having 6 to 18 carbon atoms and the monomer represented by the formula 4 are contained in a molar ratio of 5: 5 to 9: 1.

6. The adhesive composition according to item 4, wherein the acrylic monomer having a hydroxy group or a carboxyl group and an aromatic ring having 6 to 18 carbon atoms and the monomer represented by at least one of the formulas 6 and 7 are contained in a molar ratio of 5: 5 to 9: Composition.

7. The adhesive composition according to 1 above, wherein said photopolymerization initiator is a radical photopolymerization initiator comprising at least one selected from the group consisting of acetophenone, benzophenone, thioxanthone, benzoin and benzoin alkyl ether.

8. The adhesive composition of 1 above, further comprising a polyfunctional acrylic monomer.

9. The adhesive composition according to 1 above, wherein the shrinkage upon curing is not more than 3%.

10. The adhesive composition according to 1 above, wherein the acrylic monomer having a hydroxy group or a carboxyl group and an aromatic ring having 6 to 18 carbon atoms is contained in an amount of 50 to 90% by weight based on the total weight of the photopolymerizable compound.

11. A composite polarizer comprising a polarizer and a patterned retardation layer bonded to one side of the polarizer through an adhesive composition of any one of claims 1 to 10 above.

12. The composite polarizer of claim 11, wherein the polarizer is formed by bonding a protective film or a film having a function of a retardation film to a surface opposite to a surface bonded to the patterned retardation layer.

13. The composite polarizer of claim 12, wherein the patterned retardation layer comprises a liquid crystal coating layer containing a reactive liquid crystal monomer containing a benzene ring.

14. The composite polarizer of claim 13, wherein the peel strength between the polarizer and the patterned retardation layer is at least 1 N / 25 mm.

15. The composite polarizer according to 14 above, wherein the patterned retardation layer does not include an alignment film.

16. An image display apparatus comprising the composite polarizer plate of the above 15.

The adhesive composition of the present invention significantly improves the bonding force between the polarizer and the patterned retardation layer when used to produce a composite polarizer plate by bonding a polarizer and a patterned retardation layer.

The composite polarizer laminated with the adhesive composition of the present invention is excellent in heat resistance and heat and humidity resistance, so that even when exposed to high temperature and high humidity conditions for a long time, peeling and bending phenomenon are suppressed.

The composite polarizing plate bonded with the adhesive composition of the present invention has a polarization function and an improved 3D stereoscopic effect at the same time.

The present invention relates to a photopolymerizable compound comprising a hydroxyl group or an acrylic monomer having a carboxyl group and an aromatic ring having 6 to 18 carbon atoms; And a photopolymerization initiator, it is possible to remarkably improve the bonding force between the polarizer and the patterned retardation layer, to improve the heat resistance and resistance to humid heat, when the polarizer and the patterned retardation layer are used to produce a composite polarizing plate And a composite polarizing plate using the adhesive composition.

Hereinafter, the present invention will be described in detail.

Adhesive composition

The adhesive composition of the present invention comprises a photopolymerizable compound.

The photopolymerizable compound according to the present invention comprises an acrylic monomer having a hydroxy group or a carboxyl group and an aromatic ring having 6 to 18 carbon atoms.

The adhesive composition of the present invention has excellent bonding strength when used for bonding a polarizer and a patterned retardation layer, and the heat resistance and the resistance to moisture and humidity are also improved by such bonding strength improvement. In the acrylic monomer according to the present invention, a hydroxy group or a carboxyl group and an aromatic ring having 6 to 18 carbon atoms are simultaneously contained in one molecule, and the hydroxy group or the carboxyl group is contained in the liquid crystal coating layer of the polarizer surface polarizer and the patterned retardation layer It is believed that this is achieved by the pi bond interaction with the benzene ring contained in the reactive liquid crystal monomer contained on the liquid crystal coating layer, forming a hydrogen bond with the polar group.

The acrylic monomer having a hydroxy group or a carboxyl group and an aromatic ring having 6 to 18 carbon atoms improves the water resistance at room temperature so that the composite polarizer prepared from the adhesive composition of the present invention can be peeled off even in the course of handling, It does not.

The acrylic monomer according to the present invention is represented by at least one of the following general formulas (1) and (2).

[Chemical Formula 1]

(Wherein R < ₁ > is hydrogen or a methyl group,

X is oxygen, -NH- or -COO-,

R ₂ is an aryl group having 6 to 18 carbon atoms which may be substituted with an alkyl group having 1 to 5 carbon atoms, a hydroxyl group, a carboxyl group or a phenyl isopropyl group)

(2)

(Wherein R < ₃ > is hydrogen or a methyl group,

X is oxygen or -NH-,

R ₄ is an alkylene group having 1 to 5 carbon atoms, which can be interrupted by -CO- or -COO-,

And R < ₅ > is an aryl group having 6 to 18 carbon atoms substituted with a hydroxy group or a carboxy group).

Specific examples of the acrylic monomer according to the present invention include the following structural formulas a-1 to a-11, which may be used alone or in combination of two or more.

[Formula a-1]

[Formula a-2]

[Formula a-3]

[Formula a-4]

[Formula a-5]

[Formula a-6]

[Formula a-7]

[Formula a-8]

[Formula a-9]

[Chemical formula a-10]

[Formula a-11]

The hydroxyl group or carboxyl group and the acrylic monomer having an aromatic ring having 6 to 18 carbon atoms according to the present invention are advantageous in that the molecular weight is relatively large and the shrinkage rate is small when cured. Depending on the structure of the individual acrylic monomers used, the shrinkage ratio may have various values, but the shrinkage rate may be 3% or less. The smaller the shrinkage percentage, the better the lower limit is, and may be, for example, more than 0%. When the shrinkage ratio is small at the time of curing, it is possible to suppress deterioration of the uniformity of the three-dimensional effect of the central portion and the terminal portion due to the stress concentration at the end portions in the production of the composite polarizing plate.

Alternatively, the photopolymerizable compound according to the present invention may further comprise a monomer which contains a hydroxy group or a carboxyl group but does not have an aromatic ring. By further including such a monomer, it is possible to further improve the bonding force by further forming a hydrogen bond with the polarizer surface polar group and the polar group contained in the liquid crystal coating layer of the patterned retardation layer.

The monomer containing a hydroxyl group and containing no aromatic ring according to the present invention may be represented by the following formula (4).

[Chemical Formula 4]

(Wherein R ₈ is hydrogen or a methyl group, X is oxygen or -NH-, R ₉ is a straight or branched alkylene group having 1 to 6 carbon atoms, and is interrupted by a cycloalkylene group having 3 to 6 carbon atoms Lt; / RTI >

Specific examples of the monomer having a hydroxyl group according to the present invention include the following formulas c-1 to c-8, which may be used alone or in combination of two or more.

[Formula c-1]

[Formula c-2]

[Formula c-3]

[Formula c-4]

[Formula c-5]

[Formula c-6]

[Formula c-7]

[Chemical formula c-8]

Meanwhile, the monomer containing a carboxyl group and not containing an aromatic ring according to the present invention may be represented by at least one of the following formulas (6) and (7).

[Chemical Formula 6]

(Wherein R < ₁₁ > is hydrogen or a methyl group),

(7)

(Wherein R ₁₂ is hydrogen or a methyl group, X is oxygen or -NH-,

R ₁₃ is a linear or branched alkylene group having 1 to 6 carbon atoms or a linear or branched alkenylene group having 2 to 6 carbon atoms and may be interrupted by -COO- or a cycloalkylene group having 3 to 6 carbon atoms) .

Specific examples of the monomer having a carboxyl group according to the present invention include d-1 to d-9 shown below, which may be used alone or in combination of two or more.

[Formula d-1]

[Chemical formula d-2]

[Formula d-3]

[Formula d-4]

[Chemical formula d-5]

In the photopolymerizable compound according to the present invention, the acrylic monomer having a hydroxy group or a carboxyl group and an aromatic ring having 6 to 18 carbon atoms and the monomer represented by the formula 4 may be mixed in a molar ratio of 5: 5 to 9: 1 , The hydroxyl group or the carboxyl group and the acrylic monomer having an aromatic ring having 6 to 18 carbon atoms and the monomer represented by at least one of the formulas 6 and 7 may be contained in a molar ratio of 5: 5 to 9: 1. When the content ratio is within the above range, the bonding force between the polarizer and the patterned retardation layer can be maximized.

On the other hand, the acrylic monomer having a hydroxy group or a carboxyl group and an aromatic ring having 6 to 18 carbon atoms is preferably contained in an amount of 50 to 90% by weight based on the total weight of the photopolymerizable compound, from the viewpoint of improving the resistance to the internal temperature.

The adhesive composition of the present invention further comprises a photopolymerization initiator.

The photopolymerization initiator is not particularly limited, and examples thereof include radical photopolymerization initiators such as acetophenone, benzophenone, thioxanthone, benzoin and benzoin alkyl ether. These may be used alone or in combination of two or more.

Specific examples thereof include acetophenone, hydroxydimethylacetophenone, dimethylaminoacetophenone, dimethoxy-2-phenylacetophenone, 3-methylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2- Methoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4-hydroxycyclophenyl ketone, Propan-1-one, 4- (2-hydroxyethoxy) phenyl-2-methyl-1- - (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4-diaminobenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, anthraquinone, 2- Anthraquinone, 2-ethyl anthraquinone, 2-t-butyl anthraquinone, 2-amino anthraquinone, 2-methyl thioxanthone, 2-ethyl thioxanthone, 2-chlorothioxanthone, Oxanone, 2,4-diethylthioxanthone, benzoin, benzoin methyl ether, Benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, diphenyl ketone benzyl dimethyl ketal, acetophenone dimethyl ketal, p- 4,6-trimethylbenzoyldiphenylphosphine oxide, fluorene, triphenylamine, carbazole, and the like, but are not limited thereto.

The available products available on the market include darocur 1173, darocur 4265, darocur BP, darocur TPO, darocur MBF, iracacure 184, irgacure 500, irgacure 2959, irgacure 754, irgacure 651, irgacure 369, irgacure 907, irgacure 1300, irgacure 754, 819, irgacure 2022, irgacure 819DW, irgacure 2100, irgacure 784, irgacure 250, and the like. These may be used alone or in combination of two or more.

The content of the photopolymerization initiator is not particularly limited and may be, for example, 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the photopolymerizable compound. If the content of the photopolymerization initiator is less than 0.1 parts by weight, the curing rate may be slowed and sufficient curing may be difficult to proceed. If the content is more than 10 parts by weight, the durability of the adhesive layer may be deteriorated.

If necessary, the adhesive composition of the present invention may further comprise a polyfunctional acrylic monomer for improving durability.

Examples of the polyfunctional acrylic monomer include, but are not limited to, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, (Meth) acrylate such as propane tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri Trifunctional monomers such as glycerol tri (meth) acrylate; Quaternary functional monomers such as diglycerin tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylol propane tetra (meth) acrylate and tetramethylol propane tetra (meth) acrylate; Pentafunctional monomers such as dipentaerythritol penta (meth) acrylate and propionic acid-modified dipentaerythritol penta (meth) acrylate; Hexafunctional monomers such as dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, and isocyanate-modified urethane hexa (meth) acrylate. These may be used alone or in combination of two or more.

The content of the polyfunctional acrylic monomer is not particularly limited and may be, for example, 0.1 to 10 parts by weight based on 100 parts by weight of the photopolymerizable compound. When the content of the polyfunctional acrylic monomer is within the above range, the durability improvement effect can be maximized.

Complex polarizer

The present invention also provides a composite polarizing plate produced using the adhesive composition.

The composite polarizing plate of the present invention comprises a polarizer and a patterned retardation layer bonded to one surface of the polarizer through the adhesive composition.

In the composite polarizing plate of the present invention, the polarizer and the patterned retardation layer are bonded to each other through the adhesive composition, and the bonding strength is excellent. In this case, as described above, the adhesive composition layer forms a hydrogen bond with the polarizer and can form a hydrogen bond and a pi bond interaction with the patterned retardation layer.

Polarizers are generally used in the display field and are not limited to specific ones as long as they can polarize incident light. For example, a film made of polyvinyl alcohol (PVA) may be prepared by dyeing iodine or a dichroic dye and stretching it in a predetermined direction. And a protective film or a film having a function of a retardation film may be bonded to a surface opposite to the surface bonded with the patterned retardation layer.

The structure of the patterned retardation layer is not particularly limited, and may include a structure commonly used in the art. For example, it may have a structure in which a substrate, an alignment film, and a liquid crystal coating layer are laminated in this order, or may be a structure that does not include an alignment film.

The patterned retardation layer is bonded so that the liquid crystal coating layer faces the polarizer.

The base material is not particularly limited as long as it is formed of a material excellent in transparency, mechanical strength, thermal stability, water shielding property, phase difference uniformity, isotropy, etc. For example, a polyolefin resin, a polyester resin, a cellulose resin, , An acrylic resin, a styrene resin, a vinyl chloride resin, an amide resin, an imide resin, a polyether sulfone resin, a sulfone resin, a polyether sulfone resin, a polyetheretherketone resin, A substrate formed of at least one material selected from the group consisting of a vinyl alcohol resin, a vinylidene chloride resin, a vinyl butyral resin, an allylate resin, a polyoxymethylene resin and an epoxy resin can be used.

When the patterned retardation layer comprises an alignment film, the alignment film is formed by a method of coating on a substrate a composition for forming an alignment film commonly used in the art, imparting orientation, and then patterning the film so as to have different orientation directions .

The orientation imparting method includes a rubbing method, a photo alignment method, and the like. The patterning method can be performed by a plurality of exposure steps using a photomask, but the present invention is not limited thereto.

The light used for exposure is not particularly limited, and for example, polarized ultraviolet radiation, ion beam or plasma beam irradiation at a predetermined angle, and irradiation with radiation may be used. It is preferable to irradiate polarized ultraviolet rays, for example.

The liquid crystal coating layer may be formed by applying a composition for forming a liquid crystal coating layer containing a reactive liquid crystal monomer (RM) or the like commonly used in the art on an alignment film and crosslinking.

The reactive liquid crystal monomer is not particularly limited, and monomers commonly used in the art can be used, but it may preferably be a monomer having a benzene ring and an ester bond.

In the case where the patterned retardation layer does not include an alignment film, a composition for forming a liquid crystal coating layer may be applied on a substrate without an alignment film, and the alignment and patterning may be simultaneously performed to form a patterned retardation layer.

In this case, the composition for forming a liquid crystal coating layer may further contain a compound capable of alignment by polarized ultraviolet light such as a linear photopolymerizable polymer for orientation.

When the patterned retardation layer does not include an alignment film, a thinner display can be realized.

The composite polarizing plate of the present invention prepared using the above adhesive composition has excellent bonding strength between the polarizer and the patterned retardation layer. For example, the peeling force between the polarizer and the patterned retardation layer can be 1 N / 25 mm or more, preferably 1 to 5 N / 25 mm.

Image display device

Further, the present invention provides an image display apparatus including the composite polarizer.

The image display device is not particularly limited and includes, for example, a stereoscopic image implementing or semi-transmission type liquid crystal display device, a plasma display device, and an organic EL display device.

The complex polarizing plate of the present invention can be used at a position where a conventional polarizing plate and a patterned retardation layer are laminated.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention and are not intended to limit the scope of the claims. It will be apparent to those skilled in the art that such variations and modifications are within the scope of the appended claims.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention and are not intended to limit the scope of the claims. It will be apparent to those skilled in the art that such variations and modifications are within the scope of the appended claims.

Example  And Comparative Example

An adhesive composition having the composition and contents shown in the following Table 1 was prepared.

division Photopolymerizable compound Photopolymerization initiator
(D) Polyfunctional acrylic monomer
(E)
(Parts by weight) A hydroxyl group or an acrylic monomer having a carboxyl group and an aromatic ring
(A) An acrylic monomer having a hydroxy group or a carboxyl group but not having an aromatic ring
(B) Other photopolymer compounds
(C) ingredient content
(Parts by weight) ingredient content
(Parts by weight) ingredient content
(Parts by weight) ingredient content
(Parts by weight) Example 1 A-1 60 B-1 40 - - D-1 One - Example 2 A-2 80 B-1 20 - - D-1 One - Example 3 A-2 70 B-2 30 - - D-2 One - Example 4 A-3 60 B-1 40 - - D-2 One - Example 5 A-1 90 B-3 10 - - D-1 One - Example 6 A-4 70 B-1 30 - - D-2 One - Example 7 A-5 70 B-4 30 - - D-1 One One Example 8 A-6 60 B-2 40 - - D-3 One One Example 9 A-7 80 B-2 20 - - D-1 One One Example 10 A-8 80 B-3 20 - - D-3 One One Example 11 A-2 90 B-1 10 - - D-1 One - Example 12 A-2 50 B-2 50 - - D-2 3 - Example 13 A-2 95 B-2 5 - - D-1 One - Example 14 A-2 40 B-3 60 - - D-1 One - Example 15 A-1 70 B-3 30 - - D-1 One - Example 16 A-2 50 B-1 50 - - D-2 One - Example 17 A-2 100 - - - - D-1 One - Comparative Example 1 - - B-5 100 - - D-2 One - Comparative Example 2 - - - - C-1 100 D-1 One - Comparative Example 3 - - - - C-2 100 D-2 One -

A-2:

A-3:

A-4:

A-5:

A-6:

A-7:

A-8:

B-1:

B-2:

B-3:

B-4:

B-5:

C-1:

C-2:

D-1: Igacure-184 (바스프사)
D-2: Igacure-369 (바스프사)
D-3: Igacure-907 (바스프사)
E: 트리메틸올프로판 트리아크릴레이트A-1:

A-2:

A-3:

A-4:

A-5:

A-6:

A-7:

A-8:

B-1:

B-2:

B-3:

B-4:

B-5:

C-1:

C-2:

D-1: Igacure-184 (BASF)
D-2: Igacure-369 (BASF)
D-3: Igacure-907 (BASF)
E: trimethylolpropane triacrylate

Experimental Example

(1) Measurement of glass transition temperature

The adhesive compositions of Examples and Comparative Examples were placed between two sheets of silicone-treated PET films and joined together by a roll laminator. UV light having a wavelength of 313 nm was irradiated at a light quantity of 2000 mJ / cm ² using a UV exposure machine (Fusion) The composition was cured.

The release films were removed and the cured adhesive layer was measured for glass transition temperature using a TGA analyzer (Q50, TA instruments).

(2) Peel force  Measure

A polyvinyl alcohol polarizer in which a patterned retardation layer (MPR32, DNP yarn) and a triacetyl cellulose protective film were bonded to one side was made to contact the liquid crystal coating layer and the polarizer, and the adhesive compositions of Examples and Comparative Examples were laminated using a roll laminator Respectively. For the evaluation, the end portion was not coated with the adhesive.

Thereafter, the adhesive composition was cured by irradiating UV at a wavelength of 313 nm at a light quantity of 2000 mJ / cm ² using a UV exposure machine (Fusion).

The peeling force was measured by cutting the prepared composite polarizing plate sample to a width of 25 mm and peeling at a rate of 300 mm / min in a 180 degree peeling direction.

(3) heat resistance, Humidity Durability  evaluation

A composite polarizing plate was prepared in the same manner as in Experimental Example (2), and an acrylic pressure-sensitive adhesive was coated and cured on the protective film, and then bonded to soda glass and autoclaved.

Thereafter, each of the substrates was allowed to stand at 80 ° C for 500 hours, 60 ° C, and 90% RH for 500 hours. Then, bubbles or peeling occurred on the bonding surface between the liquid crystal coating layer and the polarizer were examined. Respectively.

○: No bubbles or peeling

Δ: Bubbles or peeling were observed, but only in very small areas.

X: Bubbles or peeling can be easily confirmed with the naked eye

In the case of ○, the evaluation was made only when both the heat resistance and the heat and humidity resistance were in accordance with the above criteria. Δ and X were evaluated as Δ or X even when only one of the heat resistance and the heat and humidity resistance was in accordance with the above criteria.

(4) Three-dimensional evaluation

A composite polarizing plate was prepared in the same manner as in Experimental Example (2), and the unit patterns of the patterned retardation layer of the 32-inch 3D TV pixel and the composite polarizing plate (MPR32, DNP Co.) were aligned and bonded.

Next, an image in which the red / blue color is crossed on the 3D TV unit pixel is displayed, and the initial luminance of the image realized by only the left circular polarization or the right circular polarization is measured at 9 points including the center of the screen, And a total average luminance difference was calculated from the difference between the total luminance of the left eye image and the luminance difference of the entire right eye image (see the following equation).

D = (D _L + D _R ) / 2

D _L = | (L _C - L _e ) |, D _R = | R _C - R _e |

_{L e = (L e 1 +} L e 2 + ... + L e 8) / 8, R e = (R e 1 + R e 2 + ... + R e 8) / 8,

(Wherein,

D: total average luminance difference,

D _L : Difference in total luminance of the left eye image, D _R : Difference in luminance of the right eye image,

L _C : Luminance of the central part of the left eye image, L _e : Average luminance of the peripheral part of the left eye image,

R _C : The luminance of the center part of the right eye image, R _e : the average luminance of the peripheral part of the right eye image,

L _e 1, L _e 2, ... , L _e 8: Luminance at each point of 8 points around the left eye image

R _e 1, R _e 2, ... , R _e 8: luminance of each point of 8 points around the right eye image)

Thereafter, after leaving for 250 hours at 60 ° C, the luminance was measured again by moving the image, and the initial D value and the luminance change rate of the D value after leaving were evaluated according to the following criteria.

[Criteria for determining the three-dimensional effect based on the rate of change in brightness]

○: When the rate of change of D value is 0% or more and less than 30%, the difference of the position of 3D stereoscopic effect is not confirmed

Δ: When the D value is more than 30% to less than 60%, a decrease in the three-dimensional feeling is slightly observed

X: When the D value is more than 60%, the decrease of the 3D effect is clearly recognized.

(5) Evaluation of shrinkage rate upon curing

The adhesive compositions of the examples and comparative examples were placed between two sheets of silicone-treated PET films, joined together by a roll laminator while adjusting the bonding speed to a thickness of 30 cm to a thickness of 30 cm, and then the width before curing was measured. (fusion, Inc.) intensity 2000mJ / cm ² to the rear by UV irradiation of the 313nm wavelength of measuring a width of the adhesive after curing the adhesive composition (adhesive coating width / cured before the adhesive coating width after cure) x 100 using %, And the shrinkage percentage was calculated.

(6) Water temperature

 A composite polarizing plate was prepared in the same manner as in Experimental Example (2) and left for 24 hours under the environment of 23 ° C and 55% relative humidity. Thereafter, the absorption axis (stretching direction) of the polarizing plate was changed to 5 cm 2 cm . Then, the short sides of each sample were gripped, and 80% of the longitudinal direction was immersed in a water bath of 60 ° C for 4 hours, and then taken out to wipe out the water.

The polarizer positioned at the center of the polarizer plate is shrunk by hot water immersion, so that a region having a polarizer, which is a region where no polarizer is present between the protective films, is formed. Therefore, the distance from the end of the protective film at the center of the short side of the sample to the shrunk polarizer was measured to make it the shrink length.

Further, iodine is eluted from the peripheral portion of the polarizer which is in contact with the hot water due to the hot water immersion, resulting in a region in which the color is missing in the peripheral portion of the polarizer. The degree of discoloration was evaluated by measuring the distance from the end of the shrunk polarizer at the center of the shorter side of the polarizing plate to the area where the color unique to the polarizing plate remained, and the value was regarded as the iodine dropout length.

The sum of the shrinkage length and the iodine dropout length was defined as the total erosion length (X). That is, the total erosion length (X) is the distance from the end of the polarizing plate at the center of the short side of the polarizing plate to the area where the color unique to the polarizing plate remains. It can be judged that the smaller the shrinkage length, the iodine dropout length and the total erosion length (X), the higher the adhesiveness (water resistance at room temperature) in the presence of water. The criteria are as follows.

 ◎: total erosion length X less than 2mm.

 ○: Total erosion length X is 2 mm or more and less than 3 mm.

 Δ: Total erosion length X is 3 mm or more and less than 5 mm.

×: Total erosion length X is 5 mm or more.

division Peel force (N / 25mm) Heat resistance, heat resistance Three-dimensional feeling Shrinkage (%) Water temperature Example 1 1.8 ○ ○ 1.7 ○ Example 2 1.9 ○ ○ 1.5 ◎ Example 3 2.2 ○ ○ 1.6 ◎ Example 4 2.1 ○ ○ 1.7 ○ Example 5 2.3 ○ ○ 1.4 ◎ Example 6 1.6 ○ ○ 1.6 ◎ Example 7 1.8 ○ ○ 1.6 ◎ Example 8 2.2 ○ ○ 1.7 ○ Example 9 2.0 ○ ○ 1.5 ◎ Example 10 2.1 ○ ○ 1.5 ◎ Example 11 1.6 ○ ○ 1.4 ◎ Example 12 2.2 ○ ○ 1.8 ○ Example 13 1.1 △ ○ 1.3 ◎ Example 14 1.2 △ ○ 1.9 △ Example 15 2.1 ○ ○ 1.6 ◎ Example 16 1.5 ○ ○ 1.8 ○ Example 17 1.4 ○ ○ 1.3 ◎ Comparative Example 1 0.3 X X 2.3 × Comparative Example 2 0.2 X X 3.1 × Comparative Example 3 0.4 X X 3.3 ×

Referring to Table 2, the adhesive compositions of Examples 1 to 17 had excellent peel strength. Also, the heat resistance and the heat and humidity resistance of the bonded polarized composite polarizer were excellent, and a very good three-dimensional effect was obtained regardless of the position. It is also confirmed that the shrinkage ratio is excellent when cured.

In addition, in Examples other than Example 14, those containing a hydroxyl group or a carboxyl group and an acrylic monomer having an aromatic ring having 6 to 18 carbon atoms in a preferable amount were very excellent in water temperature resistance.

However, it was confirmed that the adhesive compositions of Comparative Examples 1 to 3 were inferior in peel strength, poor in heat resistance, and in heat and humidity resistance, and had a larger shrinkage percentage than those in Examples.

Claims (16)

A photopolymerizable compound comprising an acrylic monomer having a hydroxy group or a carboxyl group and an aromatic ring having 6 to 18 carbon atoms; And
And a photopolymerization initiator.
The adhesive composition according to claim 1, wherein the acrylic monomer is at least one of compounds represented by the following general formulas (1) and (2)
[Chemical Formula 1]

(Wherein R < ₁ > is hydrogen or a methyl group,
X is oxygen, -NH- or -COO-,
R ₂ is an aryl group having 6 to 18 carbon atoms which may be substituted with an alkyl group having 1 to 5 carbon atoms, a hydroxyl group, a carboxyl group or a phenyl isopropyl group)
(2)

(Wherein R < ₃ > is hydrogen or a methyl group,
X is oxygen or -NH-,
R ₄ is an alkylene group having 1 to 5 carbon atoms, which can be interrupted by -CO- or -COO-,
And R < ₅ > is an aryl group having 6 to 18 carbon atoms substituted with a hydroxy group or a carboxy group).
The adhesive composition of claim 1, wherein the photopolymerizable compound further comprises a monomer represented by the following formula (4):
[Chemical Formula 4]

(Wherein R ₈ is hydrogen or a methyl group, X is oxygen or -NH-, R ₉ is a straight or branched alkylene group having 1 to 6 carbon atoms, and is interrupted by a cycloalkylene group having 3 to 6 carbon atoms Lt; / RTI >
The adhesive composition of claim 1, wherein the photopolymerizable compound further comprises a monomer represented by at least one of the following formulas (6) and (7):
[Chemical Formula 6]

(Wherein R < ₁₁ > is hydrogen or a methyl group),
(7)

(Wherein R ₁₂ is hydrogen or a methyl group, X is oxygen or -NH-,
R ₁₃ is a linear or branched alkylene group having 1 to 6 carbon atoms or a linear or branched alkenylene group having 2 to 6 carbon atoms and may be interrupted by -COO- or a cycloalkylene group having 3 to 6 carbon atoms) .
[Claim 4] The adhesive composition according to claim 3, wherein the hydroxyl group or the carboxyl group and the acrylic monomer having an aromatic ring having 6 to 18 carbon atoms and the monomer represented by the formula 4 are contained in a molar ratio of 5: 5 to 9: 1.
The adhesive composition according to claim 4, wherein the hydroxyl group or the carboxyl group and the monomer having an aromatic ring having 6 to 18 carbon atoms and the monomer represented by at least one of the formulas (6) and (7) are contained in a molar ratio of 5: 5 to 9: 1.
The adhesive composition according to claim 1, wherein the photopolymerization initiator is a radical photopolymerization initiator comprising at least one selected from the group consisting of acetophenone, benzophenone, thioxanthone, benzoin and benzoin alkyl ethers.
The adhesive composition of claim 1, further comprising a multifunctional acrylic monomer.
The adhesive composition according to claim 1, wherein the shrinkage ratio during curing is 3% or less.
The adhesive composition according to claim 1, wherein the acrylic monomer having a hydroxy group or a carboxyl group and an aromatic ring having 6 to 18 carbon atoms is contained in an amount of 50 to 90% by weight based on the total weight of the photopolymerizable compound.
Polarizer, and
And a patterned retardation layer bonded to one side of the polarizer through the adhesive composition of any one of claims 1 to 10.
12. The polarizing plate of claim 11, wherein the polarizer is formed by bonding a protective film or a film having a function of a retardation film to a surface opposite to a surface bonded with the patterned retardation layer.
12. The composite polarizer of claim 11, wherein the patterned retardation layer comprises a liquid crystal coating layer containing a reactive liquid crystal monomer comprising a benzene ring.
The composite polarizer according to claim 11, wherein the peeling force between the polarizer and the patterned retardation layer is 1 N / 25 mm or more.
12. The composite polarizer of claim 11, wherein the patterned retardation layer does not comprise an alignment film.
An image display device comprising the composite polarizing plate of claim 11.